Back spacing mechanism operating means for typewriting or like machines



F. KLOSKI I'AL BACK SPACING MECHANISM OPERATING MEANS Dec. 4, 1951 FORTYPEWRITING 0R LIKE MACHINES Filed Sept; 13, 1949 Dec. 4, 1951 J. F.KLosKl ETAL 2,577,457

BACK SPACING MECHANISM OPERATING MEANS FOR TYPEWRITING OR LIKE MACHINES2 SHEETS-SHEET 2 Filed Sept. 13, 1949 ---lxlll mw m51 Patented Dec. 4,1951 UNITED STATES ATENT' OFFICE BACK SPACING MECHANISM OPERATING MEANSBIACHINES FOR TYPEWRITING OR LIKE Application September 13, 1949, SerialNov. 115,542

9 Claims.

This invention relates to back spacing mechanism operating means fortypewriting or like machines, and more particularly to means foroperating back spacing mechanism by power supplied, e` g. by an electricmotor.

An object of the invention is to provide a new and improved train ofdriving connections between a power generating machanism and the backspacing mechanism of a typewriter or like machine, the connectionsincluding cushioning means of novel construction adapted to minimizeabruptness of operation of the back spacing mechanism, avoid jamming ofthe parts, and minimize noise and vibration.

Another object of the invention is to provide, for the operation of aback spacing mechanism, a train of connected elements including a toggledevice adapted to cause the back spacing mechanism to start the carriageon its back spacing movement gradually, to then move it more rapidly,and to then decelerate it near the end of its .back spacing movement.

A further object of the invention is to provide means of the characterreferred to including a spring cushioned toggle device for transmittingdrive to the back spacing mechanism.

Other objects of the invention Iwill become apparent from a reading ofthe following description of a preferred embodiment of the invention,the appended claims, and the accompanying drawings, in which:

Figure l is a View, partly in elevation and partly in vertical section,rfore and ait of `a typewriter embodying the invention, showing onlysome of the conventional or standard typewriter parts in order toillustrate the application of mechanism embodying the invention to atypewriter construction, the parts being shown in their normal orinactivepositions;

Figure 2 is a, fragmentary, substantially horizontal sectional view onthe line 2 2 of Figure l, drawn Aon an enlarged scale;

Figure 3 is a fragmentary detail elevational view showing a cushionlever and toggle construction Iwith the parts in operated positions;

Figure 4 is a fragmentary View, partly in vertical 'seotion on kthe line'2 4 of Figure 1 and partly in elevation, showing parts of an escapementmechanism and a back spacing mechanism in their normal or inactivepositions; and

Figure 5 is a fragmentary view, partly in vertical section and partly inelevation, showing vthe escapement and back spacing mechanismsillustrated in Figure 4, but with the parts in operated or 'activepositions.

The invention may be embodied in typewriters or like machinesl ofVarious kinds, For the purposes of illustration, the invention is shownas being embodied in an oflice type typewriter haying, except for thepower generating and transmitting mechanism to be described, manyfeatures in common with the well known vRoyal Standard typewriter. Thedrawings show only enough of the standard or known typewriterconstruction to assist in illustrating the manner in which mechanismembodying the invention may be coordinated with other parts of atypewriter construction.

The known construction illustrated includes a main frame A on which acarriage B equipped with a platen C is mounted for letter spacing andreturn movements by means of a top rail I secured to the carriage, androlling upon balls 2, which in turn are adapted to roll on aframemounted bottom rail or track 3.

The carriage may be driven toward the left, that is, in theletter-spacing direction, by any suitable mechanism, for example, by aspring barrel 4 and draw band 5 of known or suitable construction.

For controlling the feeding of the carriage in letter-spacing directionto take place by letter space increments, the ,carriage is equipped witha rack 'E cooperable with an escapement mechanism generally designatedD. The rack 6 is .carried by a bail I having arms 8-8 Apivoted on thecarriage at 9--9 and Iurged by springs I-Il to rock counterclockwise asviewed in Figure 1 so as normally to hold the rack in engagement with anescapement pinion Il. The bail "l and rack 6 may be swung upwardly byany suitable means (not shown) so as to disengage the rack 6 from thepinion H to enable the carriage to be shifted manually in the usualmanner. The pinion 1 I is coupled by a ratchet ,device (not shown) withan escapement wheel I2 journaled at I3 on an escapement frame orbracketI4.

The bracket 4 is equipped with cone-shaped bearing screws Iii-45extending into conformingly shaped bearing recesses in mounting earsIS-l integral with an oscillatable escapement rocker plate Il. 'Theplate I'I is equipped with the usual fixed dog I8 and limber dog I9pivoted on the plate as at 20, and urged counterclockwise as viewedin'Figures 4 and 5 by a spring 2l interposed between a lheel 22 on thelimber dog and an ear 23 on Athe rocker plate Il. An Vabutment screw 24has threaded connection with a boss or lug 25 on the back `o-f theplatev IL and can *be adjusted A4for determiningftheglimit of' rockingof the limber dog I9 when the latter is engaged by a tooth of theescapement wheel I2. An escapement wheel check pawl 26 pivoted at 21 onthe rocker plate I1, is urged counterclockwise by a spring 28 interposedbetween ears 29 and 30 on the pa'wl 26 and plate I1 respectively.

When the rocker vplate I1 is oscillated back and forth, the dogs I8 andI9 will cooperate with the escapement wheel I2 in a well known mannerfor effecting the desired letter-spacing incremental movements of thecarriage.

With the exception of power mechanism for operating it, the back spacingmechanism may be of known construction, and, as shown, is similar to theback spacing mechanism embodied in Royal Standard manually operatedtypewriters. As shown in Figure 4, a vertically movable thrust link 3|,adapted to be operated by power in a manner to be described later, ispivoted at its upper end, as at 32, to-a bell crank lever 33 mounted torock about a pivot 34 on a fixed bracket 34a. Also mounted to rock aboutthe pivot 34, and independently of the bell crank 3,3, is a rock arm 35,the upper end of which is pivoted to a thrust bar 36, as at 31. The bar36 is bifurcated to provide upper and lower arms 36E and 36h. The upperarm 36a is provided with a pin 38 which is received in a slot 39 formedin a bracket 40 secured to the escapement bracket or frame I4, and isformed with an upwardly extending tooth 4I adapted to cooperate with theteeth on the rack 6 in a manner to be described later. The lower arm 36bof the bar 36 extends behind the bracket 46 as viewed in Figure 4, andthe upper arm 36a extends in front of the bracket 40 so that the arms36u and 361, being disposed on opposite sides of the bracket 40, guidethe thrust bar 36 for reciprocation in the direction of carriage travel.For translating rocking of the bell crank 33 rst into rocking then intoreciprocation of the thrust bar 36, the bell crank is formed with a heel33a adapted to engage a projectiontIic on the thrust bar 36. A spring 42interposed between a pin 43 on the bar 36 and an arm 44 on the bracket40 normally maintains the thrust bar 36 and rock arm 35 in the positionsshown in Figure 4.

An escapement wheel stop 45 is slotted to receive the pin 43 on the bar36 and an adjustment locking screw 46, also carried by the bar 36, thearrangement being such that the stop 45 can be variably positionedlongitudinally with respect to the bar 36, and then locked in adjustedposition.

A rack lock lever 41 is mounted to rock on an adjustable pivot pin 48carried by the bracket 40 and is formed with an arcuate upper end part41a overlying the front bar of the bail 1 but normally being maintainedfree of engagement with the bail bar by a spring 49 interposed betweenan ear 50 on the rack lock 41 and an ear I on the bracket 40.

Normally the parts are in the positions shown in Figure 4. Duringtyping, the escapement mechanism D is operated in the usual manner toenable the escapement wheel I2 and pinion II to rotate step by step inthe direction of the arrow a to eect incremental letter-spacingmovements of the carriage. In order to back space the carriageincrementally the thrust link 3I is moved upwardly in a manner describedhereinafter-so as to rock the bell crank lever 33 and arm 35, andthereby move the thrust bar 36.toward the rightas viewed in Figure 4.

During the first part of the rightwara movement of the thrust bar 36,the pin 38 will move away from the inclined left end of the slot 39 inthe bracket 40 so that the bar 36 will be free to be moved upwardly bythe spring 42 and by the turning moment imposed on the bar 36 by theheel 332L of the bell crank lever 33. In this way the tooth 4I on thebar 36 will be moved into a tooth interspace on the escapement rack 6.Also during the rightward movement of the bar 36, the right-hand end ofthe thrust bar lower arm 36b will engage the rack lock 41 and swing itclockwise about its pivot so as to move its upper arcuate portion 41*3Linto engagement with the top of the bail 1, thereby locking the bailagainst upward movement. At the same time the escapement wheel stop 45will be moved into the position shown in Figure 5 so as to preventreverse rotation of the escapement wheel I2. Continued movement of thethrust bar 36 toward the right, with its tooth 4I in engagement with therack 6, will move the carriage one letter space toward the right, thatis, in the return direction, as will be permitted by the ratchetcoupling between the escapement wheel I2 and pinion I I. When the partsare returned from the positions shown in Figure 5 to the normalpositions shown in Figure 4 by downward movement of the thrust link 3I,the ratchet coupling between the escapement wheel and pinion will holdthe carriage in the back-spaced position to which it has been moved.

In general, the parts described so far do not, in themselves, constitutethe present invention. The invention resides in other parts to bedescribed, and combinations of such other parts with each other and withparts already described.

Broadly considered, vertical reciprocation of the thrust link 3I andconsequent back spacing of the carriage are effected by power-drivenmeans, generally designated E, which are made effective by depression ofa manually operable back spacing key F. Power is transmitted from thepowerdriven means E through a train of driving connections G. Theconstruction and arrangement embodied in the train of connections G, totheA thrust link 3I so as to raise the latter and operate the associatedback spacing mechanism in the manner previously described.

The power-driven mechanism E is generally similar to but embodiesimprovements in mechanism disclosed in the copending application ofWilliam H. Kupper, Serial No. 6,066, led February 3, 1948, now PatentNo. 2,567,945, dated September 18, 1951. It includes a driving element,which operates continuously, and controllable driving connections, whichnormally are inoperative or ineffective, but which may be conditioned.

by the operator to effect operative driving connection between thecontinuously moving driving member and the train of connections G. Thedriver preferably is constituted by a continuously rotating element,more particularly a toothed snatch roll or bar 52, which may be of knownform, and which is adapted to be driven in the. direction of the arrow bin Figure 1 by any suitable means, but preferably by an electric motor(not shown) The means for transmitting drive from the driver 52 to theconnections G includes an actuator 53 which extends fore and aft of thetypewriter and above the member 52. The actuator 53.

is' pivote'd as at 5d' to a lever 55 at a point off-set relatively' toithe pivotal-mounting 5e of the leverl on a fixed frame cross bar 57. Theactuator has a forwardly extending part 58 projecting under an abutmentor guide plate 55 mounted on the frame A, to extend parallel to thesnatch roll' 52. A spring 65, interposed between'. the front end of theactuator 53 and an anchor plate 5l, yieldably urges the actuator to rockclockwise, and thus normally maintains' the actuator in the positionshown in Figure l with` its front end part 58 bearing. against theabutment or guide plate 59. Another abutment 52 is disposed below theabutment 59', and is slotted to receive and guide the lowei` extremityof the actuator part 58 for sliding movements. The lever 55 normally isheld in its inactive position, shown in' Figure' l, by a returningspring' 53 interposed'between an ear 65 on the lever and an anchorplate55 mounted on the fixed cross bar 51 by screws, one of which is shown at68. The lever 55 has a stop projection 5l engage*- ablev with a xed stopstrip 68 for limiting the returning movement of the lever under the'urge of they spring 63.

In order to apply a power impulse to the train of driving connections G,the actuator 53 is operatively but indirectly connected to the drivingmember 52, the actuator itself never engaging the driving' member.Mechanism for bringing about this operative connection includes aninterponent pawl element B5, pivoted as at 'l0 on the actuator. A springll, anchored to the actuator 53 and connected to the pawl 69', biases orurges the latter to rock clockwise so as to move its double toothed hose59a into engagement with the snatch roll 52. Normally, the pawl ismaintained out of engage'- ment with the snatch roll by the restrainingaction of a contr-ol element or tri-Eger l2 which is pivoted as at 'i3on the actuator 53. in the normal position of the trigger, its rear Yendengages a. holding surface 'le on the pawl so as to prevent the'springl-I from rocking the pawl 65 into drivetransmitting engagement withthedriving member 52. The pawl 55 is formediwith. an inclined resettercam face l5 which is located just below the holding surface lil, andwhich is acted upon by the trigger for rocking the pawlcounterclockwise, and thus resetting it in normal, inoperative position.

Operator controlled means for bringing about operative drivingconnection between the driver 52 and the actuator 53 includes themanually operable backy spacing key F pivoted as at l5 on the frame A.The key F has an upward projection 'IT disposed behind an arm 75 of an'operating lever 19, pivoted as at 85 Von a frame-mounted cross bar 8l.The lever 15 has another arm t2 on which a limber dog or flipper Stilspivoted at 818. A spring 35 urges the limber dog 83 to rock clockwise toyieldably retain it in its norrna position of rest against a limit stop85 on the lever arm 82. The dog t3 can swing counterclockwise from theposition shown in Figure l, but cannot move clockwise from thisposition. A returning spring 8l, interposed between the key F and ashort arm 88 on the leverr T5, yieldably holds the lever 'I5 and the keyF in their normal positions. When the parts are in their normalpositions the spring 8T holds the lever "i5 so that the lower end' ofthey limber dog il@ overlies a contact ear 58 on the actuator 53, andholds the key F so that a forward projection 95 on the key bears againsta cushion stop: Si

In operation, when the back spacing key F is depressed, the lever 'le isrocked clockwise to causethe flipper 83 to push the actuator $3'downwardly to an initial extent suiiicient 'to bring the trigger 'l2into engagement withthe abutment 62. This causes the trigger to'v berocked clockwise about its pivot 13, sov asfto release the pawl 69,which is then moved by the spring 'II into engagement with the snatchroll 52. TheV snatch roll then drives the pawl 69 and actuator 53as aunit so as to rock the lever 55 and operate the back spacing mechanismthrough the train of connections G. When the pawl 59 is cast off fromengagement with the snatch roll 52, the spring 60 lifts the actuator 53to bring the trigger 12 into engagement with the upper,trigger-resetting abutment 59. This causes' the trigger 12 to be rockedcounterclock Wise, so as to move itsV rearend against the resetting camface 15 ofthe pawl 59, thereby re'- storing the latter to its inactiveposition. IThe parts of the mechanism E will then be returned to theirnormal positions by the spring 53.

Means are provided for adjusting or varying the amount of drivingimpulse generated .by the power mechanism E. This variation or adjust'-ment is eiected by variably limiting the extent to which the teeth onthe actuator pawl nose 69a enter tooth intel-spaces on the snatch roll;52 under the urge of the spring 'H when the ree straint of the trigger12 on the pawl 59 is discontinued. In the form shown, the actuator 53 isprovided with a downwardly extending stop element or ringer 92 which isdisposed in front of and normally out of contact with a downiwardlyextending stop part, heel, or linger 93 on the pawl 89. When ther pawl69 is rocked clock'- wise by the spring Il so as to move the teeth onthe pawl nose 69a into snatch roll tooth interspaces, the pawl stop 93moves towardl the actuator stop 92, which may be so positioned as to beengaged by the stopl 93 to arrest rocking of the pawl 6'9- before thepawl teeth move tothe roots of the snatch roll tooth interspaces. Byvariably positioning one of the stops 92, 93, eg., by bending the stopQ2 towards or away from the stop 93, the extent tol which thel pawlteeth enter the tooth interspaces on the snatch roll can be varied.Consequently, the angle through which the snatch roll rotates while incontact with the pawl, which determines the amount of driving of thepawl and actuator 53 by the snatch roll 52, can be varied. Any suitablemeans or construction may be provided for adjusting one of the stops 92,93 relatively to the other, but in the preferred construction the stop92 is formed' in# tegrally with the actuator 53 so as to be bend-` ablektoward or awayl from the stop 93.

In typewriters or like machines in which all or some of theinstrumentalities to be operated, e. g., type bars, carriage returnmechanism, tabulating mechanism, escapement mechanism as well as backspacing mechanism, are operated by power, it may be desirable toprovidemeans for' varying collectively the extent of drivingof the severalactuator pawls corresponding to the pawl 69 and associated with thecthermechanism referred to. This may be accomplished by providing a knock-ofibar Se mounted on the main frame so as to extend under the front ends oiall of the actuators corresponding to the actuator 53 shown in Figure 1.Any suitable means (not shown), may be provided for adjustably tiltingor otherwise variably positioning the knock-ori bar 94 so that it willbe engaged by the lower ends of the actuators to control the timing yofdisengage- 7 ment of tne associated actuator pawls from the snatch roll.

The train of connections G is so arranged, constructed, and coordinatedwith the power mechanism E and back spacing mechanism as to suppress orcushion the impact or concussion Which otherwise would be transmitted-abruptly from the power mechanism E to the back spacing mechanism.Accordingly, undesirable noise and harmful shocks are prevented, anddanger of jamming of the machine with resultant damage is eliminated. Inthe construction shown, a pull link 95 is pivoted as at 98 to the lever55 and is pivoted as at 91 to a cushioned toggle device generallydesignated 98. The link 95 preferably is constructed so as to beadjustable as to length, and to this end it comprises parts 95a and 95bwhich may be adjusted longitudinally with respect to eachother by aneccentric screw 95c extending through a slot 95d in the link part 95h,and being secured in adjusted position to the link part 95a. The linkparts 95EL and 95lo may be locked in adjusted positions by screws 95eextending through slots 95 in the link part 95".

The toggle device generally designated 98 includes a toggle lever orlink 99 mounted to rock about a fixed pivot |00, and a yoke or leverpivoted as at |02 on the link 99. The yoke |0| includes a part |03formed with an ear |04 to which is secured one end of a spring |05, theother end 0f which is secured to an ear |06 on the link 99. The yoke |0|includes another part |01 to which the rear end of the link 95 ispivoted as at 91, as previously stated.

Another toggle link or lever |08 is pivoted at its lower end as at |09to the link 99, and is pivoted at its upper end as at ||0 to the lowerend of the thrust link 3|. Preferably, the pivot ||0 is of a well-knowneccentric adjusting type.

Normally, the parts are in the positions shown in Figure l, wherein thetoggle link pair constituted by the links 99 and |08 is broken and thethrust link 3| consequently is in its lower or normal position. When thekey F is depressed so as to cause the actuator mechanism E to rock thelever 55 counterclockwise in the manner previously described, the link95 will be pulled forwardly, or to the left as viewed in Figure 1. Thiswill rock the interponent yoke part |0| momentarily about its pivot |02on the toggle link 99 until the spring |05 is tensioned, Whereupon forcewill be transmitted through the spring to the toggle link 99 to rock thelatter counterclockwise about the xed pivot |00. In this manner thetoggle link pair constituted by the links 99 and |08 will bestraightened or moved to the position shown in Figure 3, causing thethrust link 3| to be moved upwardly, thereby operating the back spacingmechanism shown in Figures 4 and 5 in the manner previously described.The sudden impulse caused by quick engagement of the actuator pawl 59with the snatch roll 52 will be transmitted to the link 95 so as toaccelerate the latter quickly, but since the actuating force istransmitted through the cushion spring |05 to the toggle pair 99-|08,the starting of upward movement of the thrust link 3| will momentarilybe gradual so as to avoid harmful shocks in the operation of the backspacing mechanism. By the time the spring |05 has been fully tensionedby rocking of the interponent part |0| about the pivot |02, the thrustlink 3| will be in its full upward movement. and the back spacing tooth4| will have moved into engagement with the rack 6. Then, because of thestill broken condition of the toggle device 08, the link 3| will bemoved relatively rapidly so as to effect back spacing. As the togglelinks 99 and |08 approach their straightened positions as shown inFigure 3, the thrust link 3| will be decelerated, thereby slowing downthe back spacing movement of the carriage and bringing it gently torest. Overthrow movement of the toggle device 98 is prevented byengagement of a stop projection on the link |08 with a stop ear l |2 onthe link 99. The mutually engageable stops and ||2 limit the operationof the back spacing mechanism, but any continued driving movement of thelink following engagement cf the stops will be dissipated in or absorbedby expansion of the toggle cushion spring |05. At or near the conclusionof the back spacing movement, the pawl lS9 will become disengaged fromthe snatch roll 52 in the manner previously described and the spring 63will return the mechanism E and connection train G to their startingpositions.

If the key F should be depressed and the actuator 53 and pull link 95operated when the carriage is blocked at the limit of its return travelby the usual margin stop equipment, with resultant blocking of thethrust bar 35 and associated parts of the back spacing mechanism, thespring |05 will yield to enable the link 95 to reciprocate idly Withoutjamming or damaging the parts.

The mechanism disclosed embodies the invention in a preferred form, butit is intended that the disclosure be illustrative rather than de-vnnitive, the invention being defined in the claims.

We claim:

1. In power operating mechanism for a typewriter or like machine, acarriage back spacing mechanism; a driving member; an actuator; meansincluding a cushioned motion-transmitting connection interposed betweensaid actuator and said back spacing mechanism; an interponent mounted onsaid actuator for movements into and out of operative engagement withsaid driving member and being biased to move into engagement therewith;a trigger normally maintaining said interponent disengaged from saiddriving member; a manually operable back spacing control element; meansresponsive to depression of said element for actuating said trigger torelease said interponent and enable it to move into engagement with saiddriving member, whereby said actuator will be driven by said drivingmember so as to operate said back spacing mechanism; and triggerre-setting means effective upon return movement of said element whensaid driving member is stationary for moving said trigger reversely toits releasing movement and thereby disengaging said interponent fromsaid driving member.

2. In a power operating mechanism for a typewriter or like machine; acarriage back spacing mechanism; a rotatable driving member; a movablymounted actuator; means including a cushioned motion-transmittingconnection interposed between said actuator and said back spacingmechanism; an interponent mounted movably on said actuator; a springurging said interponent to move into drive-transmitting engagement withsaid driving member; a trigger mounted movably on said actuator andnormally occupying a position in which it maintains said interponent outof drive-transmitting engage.

`ment with said driving member; an abutment;

and manually controlled means for imparting to said actuator suiiicientinitial movement to move l said trigger into engagement with saidabutment to thereby move said trigger on said actuator' and release saidinterponent to enable the latter to be moved by said spring intodrive-transmitting engagement with said driving member, whereby saidactuator will be driven by said driving member so as to operate saidback spacing mechanism.

3. In a power operated typewriter or like machine, a carriage backspacing mechanism; a driving member; a train of connections between saiddriving member and said back spacing mechanism including an actuatordrivable by said driving member, a rst pivoted lever, means connectingsaid lever to said back spacing mechanism, a second lever, meanspivotally mounting said second lever on said rst lever at a point spacedfrom the pivotal axis of said first lever, a force transmitting andcushioning spring interposed between and connecting said levers, andmeans operatively connecting said second lever to said actuator andbeing operable by said actuator to rock said second lever whereby totransmit force through said spring to said rst lever to rock the latterand operate said back spacing mechanism; and manually operable means forcontrolling transmission of drive from said driving member to saidactuator.

4. In a power operated typewriter or like machine, a carriage backspacing mechanism; a continuously driven rotary toothed snatch roll; atrain of connections between said snatch roll and said back spacingmechanism including an actuator normally disconnected from said snatchroll but being controllably connectable therewith substantiallyinstantaneously, whereupon the actuator is abruptly accelerated fromrest position, a iirst pivoted lever, means connecting said lever tosaid back spacing mechanism, a second lever, means pivotally mountingsaid second lever on said rst lever at a point spaced from the pivotalaxis of said rst lever, a force transmitting and cushioning springinterposed between and connecting said levers, and means operativelyconnecting said second lever to said actuator and being operable by saidactuator to rock said second lever whereby to transmit force throughsaid spring to said rst lever to rock the latter and operate said backspacing mechanism; and manually operable means for controllingconnecting of said actuator to said snatch roll.

5. In a power actuated typewriter or like ma- 4 chine, a carriage backspacing mechanism; a driving member; a train of connections between saiddriving member and said back spacing mechanism including an elementoperable by said driving member, and a toggle device constituted by twotoggle links pivoted together and respectively connected to said elementand said back spacing mechanism; mutually engageable stop parts on saidlinks for limiting straightening of the toggle device; and manuallyoperable means for controlling transmission of operating effort fromsaid driving member to said element.

6. In a power operated typewriter or like machine, a carriage backspacing mechanism; a driving member; a train of connections between saiddriving member and said back spacing mechanism including an elementoperable by said l0 driving member, a toggle device constituted by twotoggle links pivoted together, means connect ing one of said links tosaid back spacing mechanism, mutually engageable stop parts on saidlinks for limiting straightening of the toggle device, and a cushioningforce transmitting spring interposed between said element and the otherof said links; and manually operable means for controlling transmissionof operating effort from said driving member to said element.

7. In a power operated typewriter or like machine, a carriage backspacing mechanism; a driving member; a train of connections between saiddriving member and said back spacing mechanism including an elementoperable by said driving member, a iirst toggle link mounted to rockabout a fixed pivot, a second toggle link pivotally connected to saidfirst toggle link and to said back spacing mechanism, an interponentpivotally mounted on said rst toggle link, means connecting saidinterponent to said element to be operable thereby, and a cushioningforce transmitting spring interposed between said interponent and saidirst toggle link; and manually operable means for controllingtransmission of operating eiort from said driving member to saidelement.

8. In a power operated typewriter or like machine, a carriage backspacing mechanism; a driving member; and a train of connections betweensaid driving member and said back spacing mechanism including an elementoperable by said driving member, a first toggle link mounted to rockabout a fixed pivot, a second toggle link pivotally connected to saidfirst toggle link and to said back spacing mechanism, an interponentpivotally mounted on said iirst toggle link, means connecting saidinterponent to said element to be operable thereby, a cushioning forcetransmitting spring interposed between said interponent and said firsttoggle link for rocking the latter to straighten the toggle formed bysaid two links and thereby operate said back spacing mechanism, andmutually engageable stop parts on said links for limiting straighteningof the toggle.

9. In a typewriter or like machine, a carriage back spacing mechanism;an operating member; and a train of connections between said operatingmember and said back spacing mechanism including a rst toggle linkmounted to rock about a xed pivot, a second toggle link pivotallyconnected to said first toggle link and to said back spacing mechanism,an interponent pivotally mounted on said rst toggle link, meansconnecting said interponent to said operating member to be operablethereby, and a cushioning force transmitting spring interposed betweensaid interponent and said rst toggle link.

JOHN F. KLOSKI. WILLIAM H. KUPPER.

REFERENCES CITED The following references are of record in the iile ofthis patent:

UNITED STATES PATENTS Number Name Date 1,614,475 Hokanson Jan. 18, 19271,667,007 Hokanson Apr. 24, 1928 1,781,571 Degener Nov. 11, 19301,984,410 Hart Dec. 18, 1934

